1. Field of the Invention
The present invention relates to a coating treatment method of applying a coating solution on a substrate, a computer-readable storage medium, and a coating treatment apparatus.
2. Description of the Related Art
For example, in a photolithography process in manufacturing processes of a semiconductor device, resist coating treatment for forming a resist film by applying a resist solution on, for example, a semiconductor wafer (hereinafter, referred to as a “wafer”), exposure processing for exposing the resist film to a predetermined pattern, developing treatment for developing the exposed resist film, and so on are sequentially performed, whereby a predetermined resist pattern is formed on the wafer.
In the aforesaid resist coating treatment, often used is a so-called spin coating method of applying a resist solution on the wafer by supplying the resist solution from a nozzle to a center portion of the rotated wafer and diffusing the resist solution on the wafer by a centrifugal force.
As a method of uniformly applying a small amount of resist solution in this spin coating method, the following coating treatment method of executing a first step to a third step has been proposed. First, in the first step, the resist solution is supplied to the center portion of a wafer which is rotated at high speed at a first rotation number and diffused on the wafer. In this first step, the resist solution is not diffused to the end of the wafer yet because the amount of the resist solution supplied on the wafer is small. Subsequently, in the second step, the rotation of the wafer at low speed is once decelerated to a second rotation number, and the supply of the resist solution in the first step is continuously performed to improve the fluidity of the resist solution on the wafer. Thereafter, the supply of the resist solution in the second step is stopped, and the rotation of the wafer is then accelerated to a third rotation number to diffuse the resist solution over the entire front surface of the wafer to thereby apply the resist solution on the wafer (see Japanese Patent Application Laid-open No. 2008-71960).